Phase compensation system

ABSTRACT

Systems and methods are provided for a three-phase compensation system, whereby an electric circuit is configured to be connected with three input phases of a power source and to supply three respective output phases, said electric circuit further configured to compensate for one or two malfunctioning input phases of said three input phases by supplying current from a functioning input phase of said three input phases to replace a malfunctioning input phase.

FIELD OF THE INVENTION

The present invention generally relates to power grid backup systems andspecifically to a three-phase compensation system.

BACKGROUND

A common problem consumers of three-phase power supply often encounteris the “loss” of a phase. Sometimes, one (or even two) of the phasessupplied by the power provider malfunctions. In such a case, consumersmay use substituting power sources such as, for example, a generator inorder to compensate for the “lost” phase(s). Consumers who have noalternative power provider stay without electricity which should havebeen provided by the “lost” phase(s).

GB Pub. Num. 367455 describes substituting sources in service. In asystem, such as a ship propulsion system, having main and auxiliarygenerators driven by a common prime mover, such as a diesel engine, andhaving a second auxiliary generator which may form part of a similarset, a load circuit which has to be continuously supplied isautomatically transferred from one auxiliary generator to another if thevoltage of the first falls below a given value when the second machineis generating an adequate voltage.

GB Pub. Num. 396759 describes systems depending upon statictransformers. A 3 phase/4 phase/3 phase overhead line transmissionsystem in which the 4-phase high tension current is carried by at leastfour conductors and a ground wire, includes protective arrangementsincorporating a “balanced beam ” relay whereby, on a fault occurring ona line, that line and the line carrying the “quarter-phase” associatedwith it are disconnected and earthed, the system then operating as a3phase/2-phase 3 wire/3-phase system. If a spare pair of conductors isavailable they may replace the broken down conductor and associatedline.

GB Pub. Num. 413723 describes an electric relay arrangement responsiveto the phase relationship between corresponding voltages of twothree-phase systems involves a mechanically balanced relay having acontact member differentially controlled by two coils respectivelyenergized in accordance with two voltages whose magnitudes are dependenton such phase relationship.

GB Pub. Num. 597302 describes relay apparatus for connecting a networkto supply mains when the voltage of the former is lower by apredetermined amount than that of the latter, comprises an inductionrelay having a plurality of electromagnets, one of said magnets having awinding connected across the supply mains or the network and another ofsaid magnets having a winding supplied with current proportional to thedifference in voltage between the network and the supply mains to causethe relay to operate a circuit-breaker connected between the mains andthe network.

RU Pub. Num. 66619 describes three-phase power factor correctorcomprising a power inverter unit, power sensors ranging power supply andcontrol system, characterized in that the node power inverter unitconsists of two power inverter modules, each of which contains six keyelements included three-phase bridge circuit, three-phase inductor and astorage capacitor with a voltage sensor and control system comprises aunit ADC block determine the reference compensating current with PIvoltage on the capacitor, the current PID controllers and the unitvector pulse width modulation, the output of the ADC is connected to theinputs of the block determine the reference equalizing currents with PIvoltage on the capacitor, the output of which is connected via a currentblock of PID controllers to the input of the block vector pulse-widthmodulation, which is the final output block management.

RU Pub. Num. 2122273 describes a device which has three under-voltagerelays with make and break contacts, correcting capacitors,phase-shifting reactors, and transient-load terminals Three newlyintroduced phase-correcting capacitors are inserted betweenphase-shifting reactors and three-phase load terminals; each capacitoris shorted out by parallel-connected make contacts of under-voltagerelays of inherent and lagging phases; each phase-shifting reactor isshorted out by parallel-connected contacts of under-voltage relays ofadjacent phases.

RU Pub. Num. 2340063 describes a device containing terminals of networkA, B, C, three voltage-check relays with group of normally closed, groupof normally open and additional group of contacts, common capacitor,phase throttles and input terminals Thus network terminals are connectedto AC source, each relay is connected on phase voltage between similarphase and neutral wire. Common capacitor is connected between previousand recovered phases. Phase throttles are connected in break ofcorresponding phases between network terminals and input terminals. Andthrottle of recovered phase is bridged. Throttles of composite phasesare used for additional turn of adjacent phase voltage vectors.

RU Pub. Num. 2353038 describes a device including network terminals,three voltage control relays, three phase chokes, a contact unit withtwo groups of contacts having common contact points and a commoncapacitor. The first group of contacts contains three pairs of normallyclosed contacts, while the first pair includes serial connection of thefirst relay contact with the second relay contact, the second pair—thesecond relay contact with the third relay contact, the third pair—thethird relay contact with the first relay contact. Besides, all pairinputs are coupled with the corresponding phases, while theiroutputs—with common point of the first group of contacts. The secondgroup of contacts includes also three pairs of contacts. In addition,the first pair includes serial connection of the first relay closedcontact and open contact the second relay, the second pair—closedcontact of the second relay contact and open contact of the third relay,the third pair—closed contact of the third relay and open contact of thefirst relay. Besides, inputs from all pairs are coupled withcorresponding phases, while their outputs are connected to the commonpoint of the second group of contacts. There is a common capacitor beingconnected between the common point of the first group and common pointof the second group.

RU Pub. Num. 2551351 describes a device comprising network terminals,three fast-operate fast-release voltage relays with closing and openingcontacts, seven repeater relays per a phase with closing and openingcontacts, three phase-recovering capacitors, three phase-shiftingchokes, three phase-compensating capacitors, terminals for theconnection of a three-phase load and a power supply source. The voltagerelays are coupled to phase voltage of the respective phases in thenetwork, the phase-recovering capacitors are coupled to linear voltage,at that each of the capacitors is connected in series to an openingcontact of the repeater relay of the respective phase, each of thephase-shifting chokes is shunted by the closing contacts of the firstand second repeater relays of the respective phase and by the in-seriesclosing contacts of the third and fourth repeater relays of therespective phase, the repeater relays are connected to the negativeoutput of the power supply source directly and to the positive outputthrough the closing contacts of the voltage relay respectively. Eachphase-compensating capacitor is shunted by the closing contacts of thefifth and sixth repeated relay of the respective phase and thephase-shifting capacitor of each phase is coupled between the same phaseof the network and the phase next to the retarding phase through theopening contact of the seventh repeated relay of the respective phase.

SU Pub. Num. 633110 describes an automatic redundancy arrangement forpower supply source

None of the above offer to compensate for the “lost” phase(s) using theother available phase(s).

There is a long felt need for a compensation system enabling a consumerto receive a three-phase power supply in cases where one or two of thethree phases malfunctions without using substituting power provider(s).

SUMMARY

According to an aspect of the present invention there is provided athree-phase compensation system, comprising: an electric circuitconfigured to be connected with a three-phase power source configured tosupply three phase of a three-phase power supply in the absence of oneor two of the three phases.

The three-phase power source may comprise one of a three-phase generatorand a three-phase alternator.

The electric circuit may comprise first, second and third control relaysconnected with each other, each comprising first and second normallyopen contact inputs, first and second normally open contact outputs,first and second normally closed contact inputs, first and secondnormally closed contact outputs, a control contact input and a controlcontact output. (Hereinbelow, “contact inputs” or “contacts” for shortare also referred to as “in-contacts”. Also, “contact outputs” or“contacts” for short are also referred to as “out-contacts”.)

According to another aspect of the present invention there is provided amethod of compensating for a lost phase, comprising: providing athree-phase compensation system, comprising: an electric circuitcomprising first, second and third control relays connected with eachother; the electric circuit configured to be connected with consumersand with a three-phase power source configured to supply three phases,one to each of the first, second and third control relays respectively;and when one of the three phases does not supply current to itsrespective control relay, compensating for the malfunctioning phase bysupplying current from one of the other two control relays.

The three-phase compensation system may be configured to connect to thethree-phase power source as generated by one of a three-phase generatorand a three-phase alternator.

The first, second and third control relays may each comprise first andsecond normally open contact inputs, first and second normally opencontact outputs, first and second normally closed contact inputs, firstand second normally closed contact outputs, a control contact input anda control contact output.

According to another aspect of the present invention there is provided amethod of compensating for a lost phase, comprising: providing athree-phase compensation system, comprising: an electric circuitcomprising first, second and third control relays connected with eachother; the electric circuit configured to be connected with consumersand with a three-phase power source configured to supply three phases,one to each of the first, second and third control relays respectively;and when two of the three phases do not supply current to theirrespective control relays, compensating for the malfunctioning phases bysupplying current from the remaining control relay.

The three-phase power source may comprise one of an electricity company,a three-phase generator and a three-phase alternator.

The first, second and third control relays may each comprise first andsecond normally open contact inputs, first and second normally opencontact outputs, first and second normally closed contact inputs, firstand second normally closed contact outputs, a control contact input anda control contact output.

BRIEF DESCRIPTION OF DRAWINGS

For better understanding of the invention and to show how the same maybe carried into effect, reference will now be made, purely by way ofexample, to the accompanying drawings.

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of the preferred embodiments of the presentinvention only, and are presented in the cause of providing what isbelieved to be the most useful and readily understood description of theprinciples and conceptual aspects of the invention. In this regard, noattempt is made to show structural details of the invention in moredetail than is necessary for a fundamental understanding of theinvention, the description taken with the drawings making apparent tothose skilled in the art how the several forms of the invention may beembodied in practice. In the accompanying drawings:

FIG. 1 shows a schematic block diagram of an exemplary existingdistribution board;

FIGS. 2A and 2B show schematic block diagrams of two exemplaryimplementation options of the three-phase compensation system of thepresent invention in the exemplary existing distribution board of FIG.1;

FIG. 3 shows a schematic representation of the three-phase compensationsystem according to embodiments of the present invention;

FIG. 4 shows a schematic view of an IEC control relay;

FIG. 5 shows an exemplary scenario according to the representation ofFIG. 3 where there is an electric current in each phase R, S and T;

FIG. 5A shows an exemplary scenario according to the representation ofFIG. 3 where there is an electric current only in phase S;

FIG. 5B shows an exemplary scenario according to the representation ofFIG. 3 where there is an electric current only in phase T;

FIG. 5C shows an exemplary scenario according to the representation ofFIG. 3 where there is an electric current only in phase R;

FIG. 6 shows another schematic representation of a three-phasecompensation system 200A according to embodiments of the presentinvention;

FIG. 7 shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current in each phase R, S and T;

FIG. 7A shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current only in phase S;

FIG. 7B shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current only in phase T; and

FIG. 7C shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current only in phase R.

DETAILED DESCRIPTION OF THE INVENTION

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is applicable to other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting.

The present invention provides a three-phase compensation system forcases where one or two of the three phases malfunctions.

FIG. 1 shows a schematic block diagram of an exemplary existingdistribution board 100 comprising a three-phase switch 110 and athree-phase residual current device 120.

Three phases supplied by the power provider 105 (e.g. ElectricityCompany, three-phase alternator, three-phase generator etc.), passthrough the three-phase switch 110, then through the three phaseresidual current device 120 and to consumers 130 (e.g. via circuitbreakers—not shown).

FIGS. 2A and 2B show schematic block diagrams of two exemplaryimplementation options of the three-phase compensation system 200 of thepresent invention in the exemplary existing distribution board 100 ofFIG. 1.

FIG. 2A shows the three-phase compensation system 200 of the presentinvention implemented between the three-phase switch 110 and thethree-phase residual current device 120.

FIG. 2B shows the three-phase compensation system 200 of the presentinvention implemented between the three-phase residual current device120 and the consumers 130.

FIG. 3 shows a schematic representation of the three-phase compensationsystem 200 according to embodiments of the present invention,comprising: a housing 300 comprising three control relays C1, C2 and C3such as for example IEC control relay 700-K22Z available fromhttp://ab.rockwellautomation.com/Relays-and-Timers/700-K-IEC-Control-Relays.Each control relay comprises two Normally Open contact inputs, 13 and 43(also referred to hereinbelow as “normally open in-contacts”), twoNormally Closed contact inputs, 21 and 31 (also referred to hereinbelowas “normally closed in-contacts”) and a control contact input A1 (alsoreferred to hereinbelow as a “control in-contact”). Each control relayalso comprises two Normally Open contact outputs, 14 and 44 (alsoreferred to hereinbelow as “normally open out-contacts”), and twoNormally Closed contact outputs, 22 and 32 (also referred to hereinbelowas “normally closed in-contacts”). A schematic view of the control relayis presented in FIG. 4.

As can be seen in FIG. 4, the Normally Open contacts are open in theabsence of electric current and the Normally Closed contacts are closedin the absence of electric current. When an electric current passes fromcontrol contact input A1 to control contact output A2 (connected toneutral N (0)), the Normally Open contacts are closed and the NormallyClosed contacts are opened.

Referring to FIG. 3, attention is drawn to terminals of control relayC3. In normal operation, control contact input A1 receives an electriccurrent of input phase T (also referred to herein as a “phase-in”). Theelectric current passes from control contact input A1 to control contactoutput A2 connected to N (0), which causes the connections betweencontacts 13 and 14 and between contacts 43 and 44 to be closed and theconnections between contacts 21 and 22 and between contacts 31 and 32 tobe opened thus enabling the electric current of phase T to pass fromcontact 13 to contact 14 to contact 43 to contact 44 to Tout.

The same happens in control relay C2 when it receives an electriccurrent of phase S and in control relay C1 when it receives an electriccurrent of phase R.

In the absence of electric current of phase T in control relay C3, theconnections between contacts 13 and 14 and between contacts 43 and 44are open and the connections between contacts 21 and 22 and betweencontacts 31 and 32 are close. In such a case, electric current of phaseR may be supplied by:

Contact 43 of C1 to contact 21 of C3 to contact 22 of C3 to Tout. and/or

Contact 32 of C1 to contact 31 of C3 to contact 32 of C3 to Tout.

It will be appreciated that contact 43 of C1 may be alternativelyconnected to contact 31 of C3. In such a case, contact 32 of C1 isconnected to contact 21 of C3.

The connection of contacts 21 and 31 of C3 to the electric current ofphase R enables three-phase normal operation in the absence of phase Tand moreover in the absence of at least one other phase (R or S),namely, in the absence of T and S or in the absence of T and R.

The connection of contacts 21 and 31 of C2 to the electric current ofphase T enables three-phase normal operation in the absence of phase Sand moreover in the absence of at least one other phase (R or T),namely, in the absence of S and R or in the absence of S and T.

The connection of contacts 21 and 31 of C1 to the electric current ofphase S enables three-phase normal operation in the absence of phase Rand moreover in the absence of at least one other phase (T or S),namely, in the absence of R and S or in the absence of R and T.

FIG. 5 shows an exemplary scenario according to the representation ofFIG. 3 where there is an electric current in each phase R, S and T(normal operation). The electric current of phase T passes from contactA1 of C3 to contact A2 of C3 to N (0) and causes the connections betweencontacts 13 and 14 and between contacts 43 and 44 to be closed, namely,the electric current passes from Tin to contact 13 to contact 14 tocontact 43 to contact 44 to Tout. The same happens in phases S and R.

FIG. 5A shows an exemplary scenario according to the representation ofFIG. 3 where there is an electric current only in phase S. The electriccurrent of phase S passes from contact A1 of C2 to contact A2 of C2 to N(0) and causes the connections between contacts 13 and 14 and betweencontacts 43 and 44 to be closed, namely, the electric current pass fromSin to contact 13 to contact 14 to contact 43 to contact 44 to Sout. InC1 and C3 there is no electric current supplied by Rin and Tinrespectively, hence the connections between contacts 21 and 22 andcontacts 31 and 32 of C3 are closed and the connections between contacts21 and 22 and contacts 31 and 32 of C1 are closed. Electric currentsupplied by Sin passes to contact 13 of C2 to contact 14 of C2 tocontact 43 of C2 to contact 21 of C1, from contact 21 of C1 to contact22 of C1 and from there both to Rout and to contact 31 of C3 to contact32 of C3 to Tout.

The result is three-phase electric supply though only one phase isavailable.

FIG. 5B shows a similar exemplary scenario according to therepresentation of FIG. 3 where there is an electric current only inphase T.

FIG. 5C shows a similar exemplary scenario according to therepresentation of FIG. 3 where there is an electric current only inphase R.

FIG. 6 shows another schematic representation of a three-phasecompensation system 200A according to embodiments of the presentinvention, comprising: a housing 300A comprising three control relaysC1, C2 and C3 such as for example IEC control relay 700-K22Z availablefromhttp://ab.rockwellautomation.com/Relays-and-Timers/700-K-IEC-Control-Relays.Each control relay comprises two Normally Open contacts (13 and 43), twoNormally Closed contacts (21 and 31) and a control contact (A1).Attention is drawn to control relay C3. In normal operation, contact A1receives an electric current of phase T. The electric current passesfrom contact A1 to contact A2 connected to N (0), causes the connectionsbetween contacts 13 and 14 and between contacts 43 and 44 to be closedand the connections between contacts 21 and 22 and between contacts 31and 32 to be opened thus enabling the electric current of phase T topass from contact 43 to contact 44 to Tout.

The same happens in control relay C2 when it receives an electriccurrent of phase S and in control relay C1 when it receives an electriccurrent of phase R.

In the absence of electric current of phase T in control relay C3, theconnections between contacts 13 and 14 and between contacts 43 and 44are open and the connections between contacts 21 and 22 and betweencontacts 31 and 32 are close. In such a case, electric current of phaseR may be supplied by:

Contact 13 of C1 to contact 21 of C3 to contact 22 of C3 to Tout. and/or

Contact 32 of C1 to contact 31 of C3 to contact 32 of C3 to Tout.

It will be appreciated that contact 43 of C1 may be alternativelyconnected to contact 31 of C3. In such a case, contact 32 of C1 isconnected to contact 21 of C3.

The connection of contacts 21 and 31 of C3 to the electric current ofphase R enables three-phase normal operation in the absence of phase Tand moreover in the absence of at least one other phase (R or S),namely, in the absence of T and S or in the absence of T and R.

The connection of contacts 21 and 31 of C2 to the electric current ofphase T enables three-phase normal operation in the absence of phase Sand moreover in the absence of at least one other phase (R or T),namely, in the absence of S and R or in the absence of S and T.

The connection of contacts 21 and 31 of C1 to the electric current ofphase S enables three-phase normal operation in the absence of phase Rand moreover in the absence of at least one other phase (T or S),namely, in the absence of R and S or in the absence of R and T.

FIG. 7 shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current in each phase R, S and T(normal operation). The electric current of phase T passes from contactA1 of C3 to contact A2 of C3 to N (0) and causes the connections betweencontacts 13 and 14 and between contacts 43 and 44 to be closed, namely,the electric current passes from Tin to contact 43 to contact 44 toTout. The same happens in phases S and R.

FIG. 7A shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current only in phase S. The electriccurrent of phase S passes from contact A1 of C2 to contact A2 of C2 to N(0) and causes the connections between contacts 13 and 14 and betweencontacts 43 and 44 to be closed, namely, the electric current pass fromSin to contact 43 to contact 44 to Sout. In C1 and C3 there is noelectric current supplied by Rin and Tin respectively, hence theconnections between contacts 21 and 22 and contacts 31 and 32 of C3 areclosed and the connections between contacts 21 and 22 and contacts 31and 32 of C1 are closed. Electric current supplied by Sin passes tocontact 43 of C2 to contact 44 of C2 to contact 14 of C2 to contact 13of C2 to contact 21 of C1, from contact 21 of C1 to contact 22 of C1 andfrom there both to Rout and to contact 31 of C3 to contact 32 of C3 toTout.

The result is three-phase electric supply though only one phase isavailable.

FIG. 7B shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current only in phase T.

FIG. 7C shows an exemplary scenario according to the representation ofFIG. 6 where there is an electric current only in phase R.

It will be appreciated that system 200A may be implemented instead ofsystem 200 in FIGS. 2A and 2B.

It will be appreciated that the system of the present invention may beconnected to any three-phase power source such as an electricitycompany, a three-phase alternator or any other three-phase power source.

The system of the present invention may be integrated for example inhouses, ships, airplanes, etc. or in any system comprising a three-phasepower source.

It will be appreciated that in cases that one or two of the phasesmalfunction, there might be a situation where the consumers need morethan the working phase(s) can supply. In such a situation, thethree-phase switch breaks the electrical circuit due to an overload. Inorder to prevent the three-phase switch from breaking the electricalcircuit, the user may disconnect electric appliances, regardless ofwhich phase they are connected to up the a point where the workingphase(s) can supply the consumers' needs.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather the scope of the present invention isdefined by the appended claims and includes combinations andsub-combinations of the various features described hereinabove as wellas variations and modifications thereof which would occur to personsskilled in the art upon reading the foregoing description.

1. A three-phase compensation system, comprising: an electric circuitconfigured to receive three input phases of a three phase power sourcefrom which to supply three respective output phases, said electriccircuit further configured to compensate for one or two malfunctioninginput phases of said three input phases by supplying current from atleast one of functioning input phase of said three input phases tocompensate for the one or two malfunctioning input phases, wherein saidelectric circuit comprises first, second and third control relaysconnected with each other, each comprising first and second normallyopen in-contacts, first and second normally open out-contacts, first andsecond normally close in-contacts, first and second normally closeout-contacts, a control in-contact and a control out-contact.
 2. Thethree-phase compensation system of claim 1, wherein a first phase-in isconnected with said first control relay control in-contact and with saidfirst control relay first normally open in-contact; said first controlrelay first normally open out-contact is connected with said firstcontrol relay second normally open in-contact; said first control relaysecond normally open in-contact is connected with said third controlrelay first normally close in-contact; said first control relay firstnormally close in-contact is connected with said second control relaysecond normally open in-contact; said first control relay secondnormally close in-contact is connected with said second control relaysecond normally close out-contact, with said second control relay firstnormally close out-contact and with said second control relay secondnormally open out-contact; said first control relay second normally openout-contact is connected with a first phase-out, with said first controlrelay first normally close out-contact, with said first control relaysecond normally close out-contact and with said third control relaysecond normally close in-contact; said second control relay secondnormally open out-contact is connected with a second phase-out; a secondphase-in is connected with said second control relay control in-contactand with said second control relay first normally open in-contact; saidsecond control relay first normally open out-contact is connected withsaid second control relay second normally open in-contact; said secondcontrol relay first normally close in-contact is connected with saidthird control relay second normally open in-contact; said second controlrelay second normally close in-contact is connected with said thirdcontrol relay second normally close out-contact, with said third controlrelay first normally close out-contact and with said third control relaysecond normally open out-contact; said third control relay secondnormally open out-contact is connected with a third phase-out; a thirdphase-in is connected with said third control relay control in-contactand with said third control relay first normally open in-contact; saidthird control relay first normally open out-contact is connected withsaid third control relay second normally open in-contact; said firstcontrol relay control out-contact is connected with said second controlrelay control out-contact, with said third control relay controlout-contact and with neutral.
 3. The three-phase compensation system ofclaim 1, wherein a first phase-in is connected with said first controlrelay control in-contact and with said first control relay secondnormally open in-contact; said first control relay first normally openout-contact is connected with said first control relay second normallyopen out-contact, with said first control relay first normally closeout-contact and with said first control relay second normally closeout-contact; said first control relay first normally open in-contact isconnected with said third control relay first normally close in-contact;said first control relay first normally close in-contact is connectedwith said second control relay first normally open in-contact; saidfirst control relay second normally close in-contact is connected withsaid second control relay second normally close out-contact, with saidsecond control relay first normally close out-contact, with said secondcontrol relay first normally open out-contact and with said secondcontrol relay second normally open out-contact; said first control relaysecond normally open out-contact is connected with a first phase-out andwith said third control relay second normally close in-contact; saidsecond control relay second normally open out-contact is connected witha second phase-out; a second phase-in is connected with said secondcontrol relay control in-contact and with said second control relaysecond normally open in-contact; said second control relay firstnormally close in-contact is connected with said third control relayfirst normally open in-contact; said second control relay secondnormally close in-contact is connected with said third control relaysecond normally close out-contact, with said third control relay firstnormally close out-contact, with said third control relay first normallyopen out-contact and with said third control relay second normally openout-contact; said third control relay second normally open out-contactis connected with a third phase-out; a third phase-in is connected withsaid third control relay control in-contact and with said third controlrelay second normally open in-contact; said first control relay controlout-contact is connected with said second control relay controlout-contact, with said third control relay control out-contact and withneutral.
 4. A method of compensating for a lost phase of a threephase-power source, comprising providing a three-phase compensationsystem, comprising: an electric circuit comprising first, second andthird control relays connected with each other, configured to receivethree phases of the three-phase power source, one to each of said first,second and third control relays respectively, and to compensate for a amalfunctioning of one of said three phases that does not supply currentto its respective control relay, by supplying current to the respectivecontrol relay from one of the other two control relays.
 5. The method ofclaim 4, said first, second and third control relays each comprisingfirst and second normally open in-contacts, first and second normallyopen out-contacts, first and second normally close in-contacts, firstand second normally close out-contacts, a control in-contact and acontrol out-contact.
 6. The method of claim 5, wherein a first phase-inis connected with said first control relay control in-contact and withsaid first control relay first normally open in-contact; said firstcontrol relay first normally open out-contact is connected with saidfirst control relay second normally open in-contact; said first controlrelay second normally open in-contact is connected with said thirdcontrol relay first normally close in-contact; said first control relayfirst normally close in-contact is connected with said second controlrelay second normally open in-contact; said first control relay secondnormally close in-contact is connected with said second control relaysecond normally close out-contact, with said second control relay firstnormally close out-contact and with said second control relay secondnormally open out-contact; said first control relay second normally openout-contact is connected with a first phase-out, with said first controlrelay first normally close out-contact, with said first control relaysecond normally close out-contact and with said third control relaysecond normally close in-contact; said second control relay secondnormally open out-contact is connected with a second phase-out; a secondphase-in is connected with said second control relay control in-contactand with said second control relay first normally open in-contact; saidsecond control relay first normally open out-contact is connected withsaid second control relay second normally open in-contact; said secondcontrol relay first normally close in-contact is connected with saidthird control relay second normally open in-contact; said second controlrelay second normally close in-contact is connected with said thirdcontrol relay second normally close out-contact, with said third controlrelay first normally close out-contact and with said third control relaysecond normally open out-contact; said third control relay secondnormally open out-contact is connected with a third phase-out; a thirdphase-in is connected with said third control relay control in-contactand with said third control relay first normally open in-contact; saidthird control relay first normally open out-contact is connected withsaid third control relay second normally open in-contact; said firstcontrol relay control out-contact is connected with said second controlrelay control out-contact, with said third control relay controlout-contact and with neutral.
 7. The method of claim 6, wherein a firstphase-in is connected with said first control relay control in-contactand with said first control relay second normally open in-contact; saidfirst control relay first normally open out-contact is connected withsaid first control relay second normally open out-contact, with saidfirst control relay first normally close out-contact and with said firstcontrol relay second normally close out-contact; said first controlrelay first normally open in-contact is connected with said thirdcontrol relay first normally close in-contact; said first control relayfirst normally close in-contact is connected with said second controlrelay first normally open in-contact; said first control relay secondnormally close in-contact is connected with said second control relaysecond normally close out-contact, with said second control relay firstnormally close out-contact, with said second control relay firstnormally open out-contact and with said second control relay secondnormally open out-contact; said first control relay second normally openout-contact is connected with a first phase-out and with said thirdcontrol relay second normally close in-contact; said second controlrelay second normally open out-contact is connected with a secondphase-out; a second phase-in is connected with said second control relaycontrol in-contact and with said second control relay second normallyopen in-contact; said second control relay first normally closein-contact is connected with said third control relay first normallyopen in-contact; said second control relay second normally closein-contact is connected with said third control relay second normallyclose out-contact, with said third control relay first normally closeout-contact, with said third control relay first normally openout-contact and with said third control relay second normally openout-contact; said third control relay second normally open out-contactis connected with a third phase-out; a third phase-in is connected withsaid third control relay control in-contact and with said third controlrelay second normally open in-contact; said first control relay controlout-contact is connected with said second control relay controlout-contact, with said third control relay control out-contact and withneutral.
 8. A method of compensating for a lost phase of a three-phasepower source, comprising: providing a three-phase compensation system,comprising: an electric circuit comprising first, second and thirdcontrol relays connected with each other; said electric circuitconfigured to receive three phases of the three-phase power source, oneto each of said first, second and third control relays respectively, andto compensate for a malfunctioning of two of said three phases that donot supply current to their respective control relays, by supplyingcurrent to the two respective control relays from the remaining controlrelay.
 9. The method of claim 8, said first, second and third controlrelays each comprising first and second normally open in-contacts, firstand second normally open out-contacts, first and second normally closein-contacts, first and second normally close out-contacts, a controlin-contact and a control out-contact.
 10. The method of claim 9, whereina first phase-in is connected with said first control relay controlin-contact and with said first control relay first normally openin-contact; said first control relay first normally open out-contact isconnected with said first control relay second normally open in-contact;said first control relay second normally open in-contact is connectedwith said third control relay first normally close in-contact; saidfirst control relay first normally close in-contact is connected withsaid second control relay second normally open in-contact; said firstcontrol relay second normally close in-contact is connected with saidsecond control relay second normally close out-contact, with said secondcontrol relay first normally close out-contact and with said secondcontrol relay second normally open out-contact; said first control relaysecond normally open out-contact is connected with a first phase-out,with said first control relay first normally close out-contact, withsaid first control relay second normally close out-contact and with saidthird control relay second normally close in-contact; said secondcontrol relay second normally open out-contact is connected with asecond phase-out; a second phase-in is connected with said secondcontrol relay control in-contact and with said second control relayfirst normally open in-contact; said second control relay first normallyopen out-contact is connected with said second control relay secondnormally open in-contact; said second control relay first normally closein-contact is connected with said third control relay second normallyopen in-contact; said second control relay second normally closein-contact is connected with said third control relay second normallyclose out-contact, with said third control relay first normally closeout-contact and with said third control relay second normally openout-contact; said third control relay second normally open out-contactis connected with a third phase-out; a third phase-in is connected withsaid third control relay control in-contact and with said third controlrelay first normally open in-contact; said third control relay firstnormally open out-contact is connected with said third control relaysecond normally open in-contact; said first control relay controlout-contact is connected with said second control relay controlout-contact, with said third control relay control out-contact and withneutral.
 11. The method of claim 9, wherein a first phase-in isconnected with said first control relay control in-contact and with saidfirst control relay second normally open in-contact; said first controlrelay first normally open out-contact is connected with said firstcontrol relay second normally open out-contact, with said first controlrelay first normally close out-contact and with said first control relaysecond normally close out-contact; said first control relay firstnormally open in-contact is connected with said third control relayfirst normally close in-contact; said first control relay first normallyclose in-contact is connected with said second control relay firstnormally open in-contact; said first control relay second normally closein-contact is connected with said second control relay second normallyclose out-contact, with said second control relay first normally closeout-contact, with said second control relay first normally openout-contact and with said second control relay second normally openout-contact; said first control relay second normally open out-contactis connected with a first phase-out and with said third control relaysecond normally close in-contact; said second control relay secondnormally open out-contact is connected with a second phase-out; a secondphase-in is connected with said second control relay control in-contactand with said second control relay second normally open in-contact; saidsecond control relay first normally close in-contact is connected withsaid third control relay first normally open in-contact; said secondcontrol relay second normally close in-contact is connected with saidthird control relay second normally close out-contact, with said thirdcontrol relay first normally close out-contact, with said third controlrelay first normally open out-contact and with said third control relaysecond normally open out-contact; said third control relay secondnormally open out-contact is connected with a third phase-out; a thirdphase-in is connected with said third control relay control in-contactand with said third control relay second normally open in-contact; saidfirst control relay control out-contact is connected with said secondcontrol relay control out-contact, with said third control relay controlout-contact and with neutral.